The objective of the proposed research is to analyze brain catecholamine systems controlling feeding behavior, with respect to their neuroanatomical substrates, their specific function, and their interaction endocrine systems. Previous work has indicated that hypothalamic catecholamine injections produce antagonistic effects on feeding behavior. These effects have recently been demonstrated with several psychotropic drugs, including antidepressants and amphetamines, and they have been linked to specific catecholamine projections in the midbrain. The proposed research will use intracranial drug injection, lesion and knife-cut techniques, in combination with fluorescence microscopy, to analyze these systems with respect to their cell bodies of origin, their projection route through the hypothalamus, their hypothalamic receptor areas, and the direction of their efferent fibers. The function of these systems will be examined through meal pattern analyses, dietary manipulations, and chronic alterations in brain catecholamine activity. Endocrine studies will investigate the relationship between glucocorticoids and brain catecholamine alterations in feeding. This interaction will be characterized in terms of its time-course, dose dependency, steroid specificity, and brain site of action. The proposed efforts to investigate the central action of specific psychotropic drugs may establish an important foundation for future pharmacological studies of human eating disorders such as obesity and anorexia nervosa.